The NATO chief spoke at the foundation following talks with U.S. security officials. In his remarks, he stressed the importance of the nearly 70-year-old organization to America.

The alliance has guaranteed peace and stability in Europe since it was founded in 1949, Stoltenberg said. NATO was a response to aggression from the Soviet Union in the aftermath of World War II, and has morphed into an alliance seeking a stable, rules-based international climate where all nations can prosper.

The past 70 years have seen an unprecedented period of prosperity in Europe and North America, Stoltenberg said. NATO is the foundation for that prosperity. “Europe and North America together represent half of the world’s economic output,” he said. “And while we now have our disagreements over tariffs, it does not change the fact that Europe and North America are each other’s biggest trading partners.”

Ensuring a peaceful, prosperous Europe is in the interests of all parties “on both sides of the Atlantic,” he said.

“NATO allies share and support the fundamental values which are at the heart of American society,” he said.

Alliance nations are democracies, support individual liberties and abide by the rule of law. “They are the foundations of our free societies, but they are also the foundations of our engagement with the rest of the world,” the secretary general said. “These values are magnets for other countries, and lead them to join our alliance.”

After the Berlin Wall came down and the Soviet Union dissolved, former Warsaw Pact and Baltic nations joined the alliance. Nations in the Balkans and others aspire to join, he said. “NATO has helped to spread democratic values, free enterprise, and stability to millions of people in the eastern part of Europe, and this represents a historic geopolitical shift that has benefitted the United States and the world at large,” Stoltenberg said.

Finally, NATO allies are a boost to American military power. The Europeans have nearly 2 million active duty service members with cutting-edge capabilities. The European allies are on duty in Afghanistan, Iraq and Syria. They work with the United States in counter-piracy operations and in maintaining sea lines of communication and the airways.

NATO allies have strong and capable intelligence networks that work alongside American professionals. This alliance intelligence sharing runs the gamut of capabilities from tracking submariners in the Arctic to identifying terrorists, the secretary general said.

“NATO allies also hosts 28 American main operating bases across Europe,” he said. “These bases in Europe are not only for Europe, they enable the U.S. to project military power across the wider Middle East and Africa providing a clear strategic advantage in the fight against terrorism and other threats.

The classic example of this is U.S. Africa Command which is based in Stuttgart, Germany, or the U.S. 6th Fleet based in Naples. “When US troops are wounded in places like Iraq and Afghanistan, they are flown for quick treatment to Ramstein, Germany,” he said. “When thinking of the value of NATO to the United States, I am also reminded of what [Defense] Secretary [James N.] Mattis once told me that never in his entire career had he fought a war without NATO allies at his side. The U.S. never has to fight alone.”

Stoltenberg noted that the only time the alliance invoked Article 5 of the Washington Treaty establishing the alliance was in the aftermath of an attack on the United States – 9/11. “Since then, hundreds of thousands of European and Canadian soldiers have fought alongside the United States in Afghanistan,” he said. “More than a thousand have paid the ultimate price.”

NATO continues to be relevant and effective in Afghanistan, in the Defeat-ISIS coalition and in deterring Russia. “For nearly seven decades, the United States has been able to call upon its close allies and friends in NATO,” he said. “No other power can match that. No other power in the world has so many friends and allies.”